I assume you're talking about one specific web page? Try using LWP::Simple, for example (unless you have some Unix command line tools to do the same), to retrieve the page, and see what the source really looks like.

If the site returns different pages depending on the browser, you can spoof what UserAgent you're using, to get one or the other.

Still, it's not impossible that either browser actually still shows something slightly different from what it actually got — but typically not that much.